In the present state of the art, heating systems for fluid are comprised in two major groups: the one related to (1) burners using liquid fuels; and (2) the electric heaters.
In the first group of heaters there is a series of drawbacks in respect to operation of such burners. There are risks of explosions through inadequate use or careless ignition of the system; there are pollution problems generated by the burning of fuel oil, low efficiency rates when compared to other sources of heat; as well as high maintenance costs due to wear both of the burners and tubes which directly receive the flames. In addition, burners of the first group require appropriate installation and special operation sites which often demand the construction of long and complex fluid feeding lines.
As to the electric heaters, heating may be obtained by electric resistance in water or other fluids or by means of electrodes immersed in water, as in the case of boilers. The maintenance of the water used within optimum characteristics requires however constant attention so that the operation and vapor generation conditions do not deteriorate, and besides, there is the need of periodic replacement of electrodes due to wear.